The year 206 AH witnessed the establishment of a political independence (from the caliphate of Baghdad) in Iran. This year and the following years marked the pinnacle of cultural glory and the period of the sagacious rule of the Mo’tazilites in Baghdad. This phase lasted until the end of the governance of the Abbasid caliph, Mo’tasem (218-228 AH/833-842 AD) after which followed a period of imprudence and retrogression and a return to superficiality, paving the grounds for a total desertion of sagacity and judiciousness on the part of the Ashā’arites by the year 300 AH/913 AD. However, the situation in Iran was quite different. After two centuries of an apparent political dormancy which was in fact a period of cultural dynamism and growth, Iran was emerging as an independent state and was preparing itself for a golden period of cultural growth. The establishment of various Iranian dynasties laid the foundation for the growth of language, literature, and culture in the Islamic Iran. The constructive and significant role of the Āl-e Buyeh Dynasty in the areas of politics, culture, and religious growth can by no means be overlooked. Following the independence of the culture and civilization of Islamic Iran, the 3rd and 4th Centuries AH/9th and 10th Centuries AD marked a golden period of growth and development in the history of this nation, leading to its heights of glory in the 5th and 6th Centuries AH/11th and 12th Centuries AD. However, the Mongol invasion of Iran brought in a period of cultural and civilizational stagnancy and disintegration in the country. Keeping this background in consideration, the evolution of theological thought in Iran during this phase can be divided into two distinct periods:

A. The First Period From Political Independence Until the Mongol Invasion (206-616 AH/821-1219 AD):